Island



(No Model.)

P. H. MANCHESTER. INGANDBSGBNT LAMP.

No. 469,482. Patented Peb.z8,1892.

INYENTUE: MM ;Z

- WU'NEESEEI UNITED TATES PATENT OFFICE.

FREDERIO I-I. MANCHESTER, OF PROVIDENCE, rRHODE ISLAND.

INCANDESCYENT LAM P.

SPECIFIC'ATION forming part of Letters Patent No. 469,482, dated February 23, 1892.

Application filed November 4, 1891. Serial No. 410,820. (No model.)

T0 all whom'it maty concern:

Be it known that I, FREDERIO H. MAN CHES- TER, of the city of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Incandescent Lamps; and I hereby declare that the following is a full, clear, and eXact description of the same, reference being had to the accompanying drawings, forming part of this specification.

This invention has reference to improvements in the construction of the lamp-base, which is permanently secured to the bulb of the lamp.

The object of the invention is to produce a base for incandescent lamps in which the insulating-plate carrying the electric contacts will not be loosened by the expansion and contraction caused by changes of temperature or otherwise, thus avoidingthe twisting of this plate and the breakage of wires within said basei mThe further objects of this invention are to produce an incandescent-lamp base in which the electric contacts will be more durable and positive in their action against the contacts of the socket and in which the wires connecting with the incandescent film can be more readily and permanently secured to these contacts.

The invention consists in certain peculiar features of construction and the combination of novel parts and material, which will hereinafter be more fully described, and pointed out in the claim.

Figure 1 represents the improved base secured to the bulb of an incandescent lamp. Fig. 2 represents a top view of the base. Fig. 3 represents a Vertical sectional View of the base, taken at a line a b, Fig. 2.

Similar numbers of reference designate corresponding parts throughout.

In the drawings number 5 represents the shell in which thev lamp-bulb is secured. This shell is formed with the shoulder 6 and a contracted step 7, beyond which the lip 8 eXtends. The inner surface of this shell 5 may be provided with corrugations or studs adapted to be embedded in the plaster or cement by which the lamp-bulb is secured in this shell. The insulating plate or block 9 is formed of porcelain in the usual manner and has a circumferential shoulder 10 of a size to closely fit inside of the lip 8 and resting on the step 7, the lip 8 being bent over this shoulder 10 to firmly secure the insulating--plate to the shell. The insulating-plate 9 has also a central perforated stud 11, the perforation of which is extended through the plate to connect with the cavity 12 in the under side thereof, and the tapering perforations 18 and 14 are formed in the plate near the circumference of the same, these perforations being smaller at the upper surface of the plate than at the under side. The central contact is formed by a headed tube 15, which extends through the perforated stud 11 and is secured in plac-e by expanding its lower edge over the surface of the washer 16, contained in the cavity 12. Through the head of this tube 15 a small perforation is made to allow the end of the Wire 17 to pass through, this wire being secured to the tube or its head by solder. The contact-plate 18 is formed of a ring of metal surrounding the stud ll, and is secured in place by the ears 19, which extend through the perforations 13 and 14 and are bent against the tapering sides thereof, the perforation 13 being sufticiently large to admit the wire 20, which is soldered to the ear 19, held in that perforation or to the surface of the plate or ring 18. The wires 17 and 20 are connected with the ends of the filament held within the glass bulb, and as they can be drawn through the perforations in the tube and insulating-plate at the time the bulb is secured in the shell these wires can thus be prevented from crossing by the twisting of the bulb before the cement or plaster has hardened. The wires can, if necessary, be drawn perfectly tight before their ends are soldered. By the use of the porcelain insulating-plate shrinking is preV-ented and the consequent twisting and wabbling of the insulating-plate and resulting wear on the wires avoided.

Having thus described my invention, I claim as new and desire to secure by Letters Patent-- The combination,with the insulating-plate IOO 9, having' the central perforated. Stud 11 and the headed contact-tube 15 seoured therein, the contact ring or plate 18, secured to the surface of said insulating-plate 9 by the ears 19 paussing through the perfomtion 13 and 14,

and wires see-med to said contacts, of the Shell 5, having the contracted step 7 and the lip 8, adapted to be bent over the shoulder 10 of the nsulatingplae 'co secure sai pate in'place, as described.

In witness whereof I have herennto set my hand.

FREDERIO H. MANCHESTER. `Witnessesz HENRY J. MILLER, M. F. BLIGH. 

